Dredging and Sediment Disposal

Dredging is an excavation activity usually carried out underwater, in shallow seas or freshwater areas with the purpose of gathering up bottom sediments and disposing of them at a different location. This technique is often used to keep waterways navigable. It is also used as a way to replenish sand on some public beaches, where sand has been lost because of coastal erosion. While the intentions of dreging can be good, it can also have negative environmental impacts such as disturbance to aquatic ecosystems and dredge spoils containing toxic chemicals that can have an adverse effect on the disposal area.

As an alternative to disposal in a landfill, under certain circumstances, dredged sediments can be managed in accordance with a generic or case-specific beneficial use determiniation (BUD).

Dredged spoils which are determined to be uncontaminated, cease to be a solid waste and are unregulated when used as fill material. Dredge spoils which exhibit moderate levels of contamination may still be eligible for beneficial use but require a case-specific BUD. In either case, it is necessary to sample the dredged sediments and perform chemical analysis.